Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 822 · 40 questions

Remember (Find the topic, use the idea): Find the topic: circuit, safety, formula, component, program, sensor or IoT. Use that lesson’s rule — complete loop, V = I × R, P = V × I, last command wins, true → if part. Safety answers are always: low voltage, dry hands, an adult, never the mains.

1. 1.⚠️ About how many volts do home sockets in India supply? (a) 230 V (b) 1.5 V (c) 9 V (d) 12 V
2. 2.🔺 A current of 20 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
3. 3.🔺 A 20 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
4. 4.🔋 Identical cells side by side (in parallel) give … (a) half the voltage (b) no voltage (c) the same voltage (d) double the voltage
5. 5.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) series (b) parallel
6. 6.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) stays the same (c) gets smaller (d) gets bigger
7. 7.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) quick and clear for all (c) symbols are heavier (d) to hide the circuit
8. 8.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
   The temperature is 24 °C. What is shown? (a) Cool (b) Hot (c) Warm
9. 9.Which of these gives us electricity? (a) a battery (b) a mobile phone (c) a water pump (d) a refrigerator
10. 10.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire has come loose (c) the bulb is unscrewed (d) all wires are joined
11. 11.🔌 Is a servo motor an input or an output for a microcontroller? (a) output (b) input
12. 12.🔢 To plan an electronics project, what comes right after “pick a problem to solve”? (a) build it with an adult (b) list inputs and outputs (c) test it and fix it (d) draw the circuit diagram
13. 13.💡 6 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. Does bulb 1 glow? (a) Yes (b) No
14. 14.🔁 total = 0
    for i = 1 to 10 { total = total + i }
    What is total at the end?
15. 15.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
16. 16.💡 Why is house wiring done in parallel? (a) to save copper only (b) each gets full voltage (c) to make bulbs dim (d) so all go off together
17. 17.Which job is done by the power LED? (a) shows the board is on (b) keeps the voltage steady (c) brings power and code (d) runs the program
18. 18.🔍 Which is the odd one out? (a) an exhaust fan (b) a ceiling fan (c) an electric toy car (d) an LED lamp
19. 19.True or false: energy used each second is measured in volts (V). (a) False (b) True
20. 20.Which of these is a risky habit? (a) set a strong password (b) turn off unused gadgets (c) reuse one password (d) share only needed data
21. 21.True or false: a microcontroller has no screen of its own. (a) False (b) True
22. 22.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) dotted circles (c) straight lines (d) little stars
23. 23.⚡ What does an LED lamp mainly change electricity into? (a) movement (b) heat (c) sound (d) light
24. 24.True or false: to cover unused cameras is a risky habit. (a) True (b) False
25. 25.🗺️ In an input → process → output plan, is “a motion sensor signal” the input, the process or the output? (a) input (b) process (c) output
26. 26.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) False (b) True
27. 27.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they get dimmer (b) they keep glowing (c) they all go out (d) they explode
28. 28.🔍 Which is the odd one out? (a) unplug idle chargers (b) iron one shirt at a time (c) leave fridge door open (d) leave the TV on standby
29. 29.🔋 3 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
30. 30.True or false: on a cell, “usually the black wire” means the − (negative) end. (a) True (b) False
31. 31.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) when either is ON (b) only when both are ON (c) only when both are OFF (d) never
32. 32.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 360 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
33. 33.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put an iron nail across the gap. Does the bulb glow? (a) Yes (b) No
34. 34.🧮 Three equal 15 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
35. 35.🤖 Microcontroller or laptop: which one runs one small program? (a) microcontroller (b) laptop
36. 36.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
37. 37.🤖 Where does the board keep its program when the power is off? (a) the resistor (b) flash memory (c) the USB cable (d) the power LED
38. 38.🔍 Which is the odd one out? (a) a small display (b) a motion sensor (c) a buzzer (d) an LED
39. 39.🔌 Is a cotton thread a conductor or an insulator? (a) an insulator (b) a conductor
40. 40.🔺 A current of 0.2 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =

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